A new class of multisection 180° hybrids based on cascadable hybrid-ring couplers

A new class of multisection 180° hybrids is presented in this paper. It is based on the hybrid-ring coupler that has been reconfigured such that multiple sections can be conveniently cascaded together. The main limitations of the conventional hybrid-ring coupler are its limited bandwidth, large size, and the impracticably high-impedance levels required for large power-split ratios. These limitations are readily overcome using the multisection cascadable 180° hybrids. Simple design equations based on the scattering matrix and experimental verifications of the theoretical results for two-section 180° hybrids are presented